The long-term objective of this project is the improvement of procedures for qualitative and quantitative analyses of clinical and biological samples by development of a new generation of mass spectrometers whose performance surpasses that of available instruments. An ongoing phase of this endeavor (GM20850) is developing and testing a new electro-optical ion detector (EOID). Placed at the focal plane of a Mattauch-Herzog mass spectrometer, this sensor possesses electron multiplier sensitivity for simultaneous ion detection over a 36:1 mass range. In the three-year project proposed herein, the development of the EOID for mass spectrometers will be continued with the following specific aims: (1) qualify researchers; (2) modify the current MS/EOID to provide high resolution mass spectra (including the GCMS mode of operation); (3) Interface the MS/EOID with and automated sample processing system to gain experience with clinical procedure as applicable to mass spectrometry; (4) perform a prototype design of a clinical mass spectrometer as a baseline for a follow-on activity.